From c48222496b3a565385f89be80af9ad3334c8da4b Mon Sep 17 00:00:00 2001 From: Rasmus Dahlberg <rasmus.dahlberg@kau.se> Date: Sat, 2 Oct 2021 00:04:22 +0200 Subject: updated design description - Minor rephrasing and white-space changes to make raw text nicer. - Avoid using sigsum as "signed checksum" in text. Not helpful. - Removed TODO in text about Figure 2. It works without it for now. --- doc/design.md | 28 ++++++++++------------------ 1 file changed, 10 insertions(+), 18 deletions(-) diff --git a/doc/design.md b/doc/design.md index e2c0f8d..1179489 100644 --- a/doc/design.md +++ b/doc/design.md @@ -185,7 +185,8 @@ less costly to bootstrap into a reliable log ecosystem. ## 3 - Design We consider a _claimant_ that claims to distribute the _right_ opaque data with cryptographic hash X. A claimant may add additional falsifiable claims. -However, all claims must be digitally signed to ensure non-repudiation [\[CM\]](https://github.com/google/trillian/blob/master/docs/claimantmodel/CoreModel.md). +However, all claims must be digitally signed to ensure non-repudiation + [\[CM\]](https://github.com/google/trillian/blob/master/docs/claimantmodel/CoreModel.md). A user should only use the opaque data if there is reason to _believe_ the claimant's claims. Therefore, users are called _believers_. A good first step @@ -307,7 +308,7 @@ an inclusion proof leads up to. Sigsum logs have trustworthy tree heads due to using a variant of witness cosigning. A believer can not be tricked into accepting some opaque data that have yet to be publicly logged unless the attacker controls more than a threshold of witnesses. In other words, witnesses -are trust anchors that ensure verifiers see the same sigsum statements as +are trust anchors that ensure verifiers see the same signed statements as believers. Sigsum logging can facilitate detection of attacks even if a believer fails open @@ -316,10 +317,10 @@ repository mirror does not serve proofs of public logging could indicate that there is an ongoing attack against a claimant's distributed infrastructure. Interested parties can look for that. -_Monitoring_ -- as in inspecting the log for sigsums that interest you -- can be -viewed as a separate 4th step. A monitor implements the verifier role and is -necessarily ecosystem specific. For example, it requires knowledge of public -verification keys, what the opaque data is, and where the opaque data is +_Monitoring_ -- as in inspecting the log for signed statements that interest you +-- can be viewed as a separate 4th step. A monitor implements the verifier role +and is necessarily ecosystem specific. For example, it requires knowledge of +public verification keys, what the opaque data is, and where the opaque data is located. ### 3.2 - Summary @@ -332,18 +333,9 @@ tree head is correct before cosigning. Claimants, verifiers, and witnesses interact with the log using an HTTP(S) API. A claimant must prove that they own a domain name as an anti-spam mechanism. Believers interact with the log _indirectly_ through their claimant's existing -distribution mechanism. It is the claimant's job to log sigsums and distribute -necessary proofs of public logging. It is the verifier's job to look for new -statements in the log and alert an arbiter if any claim is false. - -An overview of the entire system is provided in Figure 2. -``` -TODO: add complete system overview. See drafty figure in archive. -- Make terminology consistent with Figure 1 -- E.g., s/Monitor/Verifier -- E.g., s/leaves/statements -- Add arbiter -``` +distribution mechanism. It is the claimant's job to log signed statements and +distribute necessary proofs of public logging. It is the verifier's job to look +for new statements in the log and alert an arbiter if any claim is false. ### 4 - A peek into the details Our bird's view introduction skipped many details that matter in practise. Some -- cgit v1.2.3